1. Field of the Invention
The present invention relates to multilayered structures having polycarbonate and polyamide layers; and, more particularly, relates to multilayered structures having a functionalized polyamide layer and a polycarbonate resin layer.
2. Description of Related Art
Multilayered structures having a polycarbonate layer and a polyamide layer have been employed in the past (see for example Collins, U.S. Pat. No. 4,513,037) wherein is disclosed a multilayered structure having a polycarbonate outer layer, a polycarbonate inner layer, and a polyamide intermediate layer between the two polycarbonate layers. The polycarbonate layers provide the structure with good impact strength, but typically lack desired levels of oxygen barrier properties. The polyamide layer, in particular amorphous polyamides, provides the structure with the desired levels of oxygen barrier properties, but typically lacks adequate impact strength. The multiple layer structure of Collins combines the desired properties of the polycarbonate layer and the polyamide layer to obtain a structure having both adequate impact strength and adequate oxygen barrier properties.
Multiple layered structures of a polycarbonate layer and a polyamide layer generally lack desired levels of adhesion and require the use of tie layers if adhesion is to be obtained between the layers. Tie layers however can add additional processing requirements in the creation of the structure. Multiple layered structures consisting of polycarbonate layers and polyamide layers in direct contact with each other which do not employ a tie layer have generally resulted in laminates which delaminate under stress. Thus, it is an object of the present invention to provide a multilayered structure having good direct adhesion between the polyamide layer and the polycarbonate layer comprising layers of a polycarbonate resin layer and an amine functionalized polyamide resin in direct adhering contact with each other.